.
Age-related osteoporosis, also known as Type II osteoporosis, is associated with the loss of cortical and trabecular bone (Marcus 13). This form of osteoporosis generally affects men and women above the age of 70 (Encarta 2001), and has generally been attributed to a negative calcium balance in the body (Rosen et al 490). The negative calcium balance is a result of the reduction in gut calcium absorption and an increase in renal calcium excretion (490).
Idiopathic juvenile osteoporosis, the third type of primary osteoporosis, is a rare form of the disease in which bone demineralization occurs (Marcus 96). Idiopathic juvenile osteoporosis affects primarily premenopausal women and middle-aged men (Encarta 2001), although it is more common in men (Marcus 180). The onset of idiopathic osteoporosis typically occurs in the early stages of puberty, and appears to have a direct correlation to the pubertal growth spurt (Marcus 96). Nonspecific findings of bone pain, difficulty walking, and fractures of the vertebrae and long bones are generally symptomatic of the disease (96). Diagnosis of idiopathic juvenile osteoporosis is difficult, as it is determined only after the exclusion of other causes of childhood osteoporosis, such as osteogenesis imperfecta, calcium deficiency, vitamin D deficiency, malabsorption, hyperparathyroidism, hyperthyroidism, and Cushing's syndrome (97). On a biological scale, most patients exhibit a negative calcium balance and low 1,25-dihydroxyvitamin D levels; however, the etiology (factors that contribute to the occurrence of a disease) is not known (97). Consequently, there is no established therapy for idiopathic juvenile osteoporosis; but most patients are able to recover spontaneously within three to four years (97).
Secondary osteoporosis is characterized by bone loss that results from specific clinical disorders such as paralysis, hormonal deficiencies, nutritional deficiencies, and drug therapy (Encarta 2001).
